This invention relates to ink jet printheads. More particularly, the invention relates to a method of manufacture of an ink jet printhead having a moving nozzle with an externally arranged actuator.
Our co-pending U.S. patent application Ser. No. 09/112,835 discloses a method of manufacture of a moving nozzle generally. Such a moving nozzle device is actuated by means of a magnetically responsive device for effecting displacement of the moving nozzle and, in so doing, to effect ink ejection.
A problem with this arrangement is that it is required that parts of the device be hydrophobically treated to inhibit the ingress of ink into the region of the actuator.
A method of manufacture of a moving nozzle-type device is proposed where the need for hydrophobic treatment is obviated.
According to the invention, there is provided a method of manufacture of an ink jet printhead, the method including the steps of
providing a substrate; and
creating an array of nozzle assemblies on the substrate with a nozzle chamber in communication with a nozzle opening of a nozzle of each nozzle assembly, the nozzle of each assembly being displaceable relative to the substrate for effecting ink ejection on demand and the nozzle assembly including an actuator unit connected to the nozzle and arranged externally of the chamber for controlling displacement of the nozzle.
In this specification, the term xe2x80x9cnozzlexe2x80x9d is to be understood as an element defining an opening and not the opening itself.
Preferably, the method includes creating said array by using planar monolithic deposition, lithographic and etching processes.
Further, the method may include forming multiple printheads simultaneously on the substrate.
The method may include forming integrated drive electronics on the same substrate. The integrated drive electronics may be formed using a CMOS fabrication process.
The method may include forming a first part of a wall defining the chamber from a part of the nozzle and a second part of the wall from an inhibiting means, which inhibits leakage of ink from the chamber, the inhibiting means extending from the substrate. More particularly, the method may include, by deposition and etching processes, forming the inhibiting means to extend from the substrate.
The method may include interconnecting the nozzle and the actuator unit by means of an arm such that the nozzle is cantilevered with respect to the actuator unit.
The actuator unit may be a thermal bend actuator and the method may include forming the actuator from at least two beams, one being an active beam and the other being a passive beam. By xe2x80x9cactivexe2x80x9d beam is meant that a current is caused to pass through the active beam for effecting thermal expansion thereof. In contrast, the xe2x80x9cpassivexe2x80x9d beam, has no current flow therethrough and serves to facilitate bending of the active beam, in use.